The Interior Ministry announced on Sunday that 50 million cigarette rolls were confiscated in the largest seizure in one instance in operations against bootleg cigarette production.

Rolls were discovered in a spacious warehouse in the Osmangazi district of the northwestern Turkish province of Bursa. The warehouse was serving as a secret cigarette factory where tobacco is filled into rolls by special machinery. Along with the rolls, security forces seized 6.9 tons of tobacco and seven machines used in filling the rolls. Fifteen suspects were detained in the operation, including 13 foreigners whose nationalities were not disclosed.

Announcing the operation on his social media account, Minister Süleyman Soylu congratulated the Bursa police.

The operation followed an earlier raid on May 16, in a bootleg cigarette production facility where more than 5.6 million cigarette rolls were seized and one person was arrested. After an in-depth probe, security forces launched a second raid in the early hours of Sunday.

Bootleg cigarettes are a source of concern for Turkey where cigarette price hikes turn addicts to smuggled cigarettes or those rolled and sold en masse with legally sold tobacco, something illegal in Turkey. In February, police raided what was then dubbed as the country’s biggest illegal cigarette factory in the western province of Izmir and seized more than 10 million cigarettes. Security forces routinely carry out raids against illegal sellers, who often supply legal raw tobacco, and hookah shops that have proliferated across the country in recent years.

The country managed to curb smoking rates with a landmark ban on smoking indoor venues in 2008, a long way for a country tested by the notorious habit which was once allowed even at hospitals. Yet, more than 15 million people still regularly smoke according to figures. Apart from the indoor smoking ban, the government had implemented all other options at its disposal to eradicate the addiction, from offering free treatment to addicts to placing steep taxes on tobacco products. The Health Ministry also runs a hotline for addicts, which helped 40% of callers kick the habit last year.

Figures by World Health Organization (WHO) show that 31% of fatalities among men in Turkey stem from diseases caused by smoking, while this rate is 12% for women. Every year, around 83,000 people die of illnesses linked to smoking.